Round and brash, with the gravelly voice of a street fighter, Arthur Caplan looks and sounds more like a boxer than an ethi­cal philosopher. The director of the Center for Bioethics at the University of Pennsylvania, Caplan has been enormously influential in a variety of debates in modern biomedicine, from the fate of Terri Schiavo to the market for organs for transplant. He has written or coauthored more than 400 peer-reviewed articles and several books on the ethics of new medical technologies.

TR: Why should we care about bioethicists? Are they really so influential?

Caplan: Bioethics is most influential at the bedside. But the influence of bioethicists on research and human experimentation is also strong. Finally, conservative bioethicists have a lot of influence in Washington these days.

TR: How much of this activity is just window dressing? Arguably, it allows interested parties to say, “Look, we’ve got bioethicists here! We must be taking care of the ethics!”

Caplan: Well, that happens, but it doesn’t mean bioethicists don’t make a difference. Bioethics has real influence on legislation and regulation.

TR: What debates have you most influenced?

Caplan: I was involved in the National Organ Transplant Act. I single-­handedly held up the movement toward creating markets in organs. In genetics, I was the first guy on embryonic-stem-cell research. I was able to undermine the administration’s argument that the president’s position [which allowed federal funding of stem-cell research with cell lines that were already established] was a compromise. Since then, I’ve worked with patients’ groups and scientists to find a moral framework for embryonic-stem-cell research.

TR: You have not mentioned the death of Terri Schiavo. But last year it seemed you talked of little else: you were ceaselessly quoted in the media.

Caplan: I was the most outspoken critic of government intervention, that’s true. And I felt bullied by the president and by some members of Congress. But although we were outnumbered and outspent, it’s fair to say that we won that fight. Most Americans don’t want government intervention in end-of-life cases.

TR: Why should anyone listen to bioethicists?

Caplan: Critics sometimes say, “Well, who elected you king?” I smile and say, “If you don’t like what I say, just ignore it.” Look, bioethicists became influential for a reason: they were able to bridge the gaps between politicians, the media, and the sciences. But they’re not a priesthood, and they don’t have any authority to dictate anything to anybody.

TR: Do bioethicists say no a lot?

Caplan: We jokingly say that anyone can be a bioethicist: just say no to everything.